Packer for well bores



July 25, 1961 1.. c. FONS ETAL PACKER FOR WELL BORES Filed Aug. 8, 1957INVENTOR.

United States Patent 2,993,540 PACKER FOR WELL BORES Lloyd C. Fons,Bradford, and Robert M. Macfarlane,

Lewis Run, Pa., assignors, by mesne assignments, to Sersmograph ServiceCorporation, 'Ihlsa, 0kla., a corporatlon of Delaware Filed Aug. 8,1957, Ser. No. 676,972

3 Claims. (Cl. 166-187) This invention relates to the well drilling art,and more particularly to a method of preventing movement of hquid, gas,or suspended solid material in the well bore from entering previouslyselected permeable formations that are exposed to the bore hole.

In the oil, gas, brine, and water well art, it is often desirable toseal or plug a permeable formation zone, to prevent escape of pressurefluids being admitted to the well bore. 'Such a sealing procedure may beused to stimulate production of these substances. Such a sealmgprocedure may be utilized wherein gas or liquid pressure is to beapplied upon an underground body of oil, or the like, to force it intoan adjacent well bore. By sealing the permeable formation zones of thewell bore, a pressure loss may be avoided, or greatly reduced, tothereby render the overall Operation practical, and/ or improve theefllciency thereof.

The present invention affords a means for selectively sealing, orplugging a permeable formation zone of a well bore, whereby loss ofpressure, or fluidflow may be avoided, or reduced by a considerabledegree. In addition to the possibility of selectively sealing permeableformation zones in a well bore, the present invention is characterizedby extreme simplicity 'of application, and one which affords greatereconomies in oil recovery operations.

The main object of this invention is to provide a means for selectivelysealing predetermined areas of a well bore to selectively prevent orminimize fluid flow and loss of pressure.

A further object of the invention is to provide a well bore selectivesealing means which is simple, effective, and which affords greateroverall economies in oil recovery operations. 7

These and further objects and features of the invention will become moreapparent from the following description and the accompanying drawingswherein:

FIG. 1 is a section view of well bores illustrating a device of theinvention as used to seal a permeable formation zone in one of the wellbores;

FIG. 2 is a section view illustrating the device of the invention ingreater detail, and prior to application against a permeable formationzone in a well bore;

FIG. 3 is similar to FIG. 2, but showing the device after application toa permeable formation zone of a well bore;

FIG. 4 is a section view of a device representing another embodiment ofthe invention, and prior to application against a permeable formationzone in a well bore;

FIG. 5 is the same as FIG. 6, but showing the device after applicationto a permeable formation zone of a well bore;

FIG. 6 is a section view illustrating a detail of the device of FIG. 4;

FIG. 7 is an enlarged section view as seen from line 77 in FIG. 5; and

FIG. 8 is an enlarged section view as seen from line 88 in FIG. 5.

Referring now to the drawings and more particularly to FIG. 1 numeral 11identifies a well bore which extends downwardly into the ground parallelto an adjacent well bore 12, both of which pass through the same oilPatented July 25, 1961 and water bearing formation sands 113, the oilfrom which it is desired to pump, or force to the surface of the ground.A sealing or plugging device 14, representing an embodiment of theinvention, is shown positioned in well bore 11 in front of a permeablewater bearing formation zone 16 through which the well bore 11 extends.The sealing device 14 is shown expanded and just prior to finalinstallation in the region of the per meable zone 16, and beforeplacement means, to be described in greater detail hereinafter, havebeen removed from the sealing device.

The sealing device 14, as best seen in FIG. 2, is tubular, orcylindrical in form and comprises a pair of toroidal, or doughnut-shapedend pieces 17, inter-connected by a tubular membrane, or sheath 18. Theend pieces 17, as well as the sheath 18, are formed of a flexible andexpandable material such as rubber or the like, and which is imperviousto fluid flow therethrough. A pipe, or tube 19 connects the interior ofthe end pieces 17 so that pressure fluid admitted to the upper end pieceby means of a pipe, or hose 21, can flow to the lower end .piece so thatthe pressure in each end piece 17 is equal.

Placement means in the form of a cable, or rope 22, is aflixed to theupper end piece 17 by way of an expandable link 23, an eyelet piece 24and a plurality of rope, or cable members 26. Afiixed to the lower endpiece 17 by means of rope, or cable members 27, is a weight 28, whichserves to pull the sealing device 14 downwardly in the well bore.

To apply the sealing device 14, it is lowered into the well bore 11until it is adjacent 'to the permeable formation zone 16 desired to besealed. A gas, or other pressure fluid is introduced into the end pieces17 by way of the hose 21 to expand the end pieces radially, so that theyroughly engage the wall of the well bore. Liquid or gas is then pumpedinto the top of the bore hole 11 creating a pressure differential acrossthe sealing device walls 18. The pressure in the hole on the inside ofthe device now being greater than the formation pressure causes thedevice to be pushed tightly against the bore hole wall. Next, the cable22 is pulled upwardly and is released by opening of the expandable link23. The hose 21, may also be removed at this time since the differentialpressure across the sealing sheath 18 is holding the sealing sheathagainst the wall with great force. The pressure medium which forces thesheath is against the side of the well bore, also passes downwardly toact upon the oil in the permeable oil sands 13, to force it in thedirection of the production wells.

It will be seen that the sealing device 14 of the invention may thus beutilized to seal, or plug, any predetermined region of the well bore toprevent loss of pressure, or escape of pressure fluid being used toforce the oil upwardly from an oil bearing formation zone(s) into wellbore 12. The sealing device 14 will effectively block flow of pressurefluid in the well bore 11 from escaping into a region of permeableformation, since the sheath 18, being formed of an elastic or flexiblematerial, will naturally accommodate itself to the surface of the wellbore when pressure is applied on the inside of the sheath, hence thesealing device will operate efiectively in well bores having less thanperfectly round peripheries.

Another embodiment of the invention comprising a sealing device 31,which may be utilized to achieve the same results as the sealing device1 4, is illustrated in FIGS. 4 to 8 inclusive. The main differencebetween the sealing device 31 and the one previously described, residesin the details of structure permitting initial positioning of the devicein the well bore. More particularly, instead of incorporating aninflatable end piece such as end piece 17 as used in the sealing device14, the sealing device 31 utilizes a plurality of radially disposed 3arms 32 which function somewhat in the nature of umbrella ribs to expandeach end of a tubular flexible membrane, or sheath 33. The arms 32 arepivotally aflixed at one end to a pipe, or tubing 34, which slidably'encloses a pipe, or tubing 36. A rod 37, to which the tubing 34 isaflixed by means of a set screw 35, extends through the tubing 36 andhas a weight 38 afiixed to the lowerend, and an eyelet 39 formed at theupper end.

The ends of the arms 32 are each pivotally attached to a grommet '41which are secured to the sheath 33. The tubing 34 has verticallydisposed slots 42 to slidably receive radially disposed arms 43 of aring 44, as best seen in FIG. 7. Pivotally atfixed at one end to thering 44 is a plurality of arms, or ribs 46, the other end of each armbeing pivotally aflixed to one of the arms 32.

A compression spring 47 surrounds the upper end of the rod 37 whichspring is arranged between washers 48 the upper washer being inengagement with the bottom of eyelet 39, While the lower washer is inengagement with a trigger means 49. A rope, lor cable 51, attached tothe trigger means 49, is adapted to release the trigger means fromholding engagement of the lower washer 48 allowing spring 47 to expandand cause downward movement of the tubing 36 relative to the rod 37. Asa result, the arms 43 will move downwardly and cause arms 46 to swingthe arms 32 outwardly, whereby the upper and lower end regions of thesheath 33 will be brought into engagement with the wall of the well bore11. A pressure fluid is then admitted to the well bore 11, which forcesthe sheath against the wall of the well bore 11, as illustrated in FIG.5, to thereby seal the zone of permeable formation against fluid flowtherein.

The cable 22 is then pulled upwardly and released by opening of theexpandable link 23. In such manner the sealing device 31, may be appliedto a predetermined zone in the well bore.

From the foregoing it will be seen that the invention provides a meansfor selectively sealing permeable zones of a well bore to prevent flowof pressurized medium into said zones, and that the method of theinvention aifords extreme simplicity of application, and contributes togreater economies in oil recovery operations.

The foregoing description has been given in detail without thought oflimitation since the inventive principles involved are capable ofassuming other physical embodiments without departing from the spirit ofthe invention and the scope of the appended claims.

What is claimed is:

I 1. A sealing device for a well bore comprising an impermeable andexpansible open ended cylindrical sheath,

a toroidal shaped expansible element arranged within and connected toeach end of the sheath, said toroidal shaped element being expansibleradially outwardly from the center of the toroidal shaped element, meansfor admitting pressure fluid to the interior of said toroidal shapedexpansible elements whereby the ends of the sheath will be brought intocontact with the wall of a well bore, means for holding said sheathvertically distended, and a cable means for lowering the sealing deviceinto a well bore to a predetermined depth.

2. A sealing device for a well bore comprising an impermeable andexpansible open ended cylindrical sheath having an integral toroidalshaped element formed around the inside of each end thereof, saidtoroidal shaped element being expansible radially outwardly from thecenter of the toroidal shaped element, means interconnecting theinteriors of the toroidal shaped elements, a pressure line for admittingfluid under pressure to the toroidal shaped elements to cause saidradial expansion thereof whereby the ends of the sheath may be broughtinto contact with the wall of a well bore, a cable releasably aflixed tothe upper end of the sealing device for lowering it into a well bore,and a weight attached to the lower end of the sealing device.

3. A sealing device for a well bore comprising an impermeable andexpansible open ended tubular sheath having an integral toroidal shapedportion around the inside of each end, said toroidal shaped portionbeing expansible radially outwardly from the center of the toroidalshaped portion, a hose interconnecting the interiors ot the toroidalshaped end portions, a pressure line removably aflixed to the uppertoroidal shaped element for admitting fluid under pressure to cause saidradial expansion of said toroidal shaped end portions whereby the endsof the sheath may be brought into contact with the wall of a well bore,a cable releasably aflixed to the upper toroidal shaped end portion forlowering the sealing device into a well bore, and a weight aflixed tothe lower toroidal shaped element.

References Cited in the file of this patent UNITED STATES PATENTS

